System and method for controlling trim position of propulsion device on a marine vessel

ABSTRACT

A method of controlling trim position for a propulsion device on a marine vessel includes receiving a running trim position for the propulsion device, receiving at least one of a steering input value or a roll angle of the marine vessel, and determining a magnitude of the steering input value or a magnitude of the roll angle of the marine vessel. The method further includes determining an adjusted trim position based on the magnitude of the steering input value or the magnitude of the roll angle of the marine vessel, and operating a trim actuator based on the adjusted trim position to decrease the trim angle of the propulsion device below the running trim position while the marine vessel is turning.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.15/243,285, filed Aug. 22, 2016, which is incorporated herein byreference in entirety.

FIELD

The present disclosure relates to systems and methods for controllingtrim position of trimmable propulsion device with respect to a transomof a marine vessel.

BACKGROUND

U.S. Pat. No. 6,322,404, incorporated by reference herein, discloses aHall effect rotational position sensor is mounted on a pivotable memberof a marine propulsion system and a rotatable portion of the rotationalposition sensor is attached to a drive structure of the marinepropulsion system. Relative movement between the pivotable member, suchas a gimbal ring, and the drive structure, such as the outboard driveportion of the marine propulsion system, cause relative movement betweenthe rotatable and stationary portions of the rotational position sensor.As a result, signals can be provided which are representative of theangular position between the drive structure and the pivotable member.

U.S. Pat. No. 7,156,709, incorporated by reference herein, discloses thecalibration procedure allows an upward maximum limit of tilt to beautomatically determined and stored as an operator rotates a marinepropulsion device relative to a marine vessel with a particularindication present. That indication can be a grounded circuit pointwhich informs a microprocessor that at calibration procedure isoccurring in relation to an upward trim limit. When the ground wire isremoved or disconnected from the circuit point, the microprocessor knowsthat the calibration process is complete. During the rotation of theoutboard motor or marine propulsion device in an upward direction, boththe angular position of the outboard motor and the direction of changeof a signal from a trim sensor are stored.

U.S. Pat. No. 7,416,456, incorporated by reference herein, discloses anautomatic trim control system changes the trim angle of a marinepropulsion device as a function of the speed of the marine vesselrelative to the water in which it is operated. The changing of the trimangle occurs between first and second speed magnitudes which operate asminimum and maximum speed thresholds.

U.S. Pat. No. 8,011,982, incorporated by reference herein, discloses asupport system for an outboard motor provides a restricted member thatis attached to a bottom portion of the outboard motor and a restrictingmember that is attached to a support structure that is, in turn,attached to a transom of a marine vessel. The restricted member isprevented from moving in a starboard or port direction by a magnitudegreater than a preselected magnitude that is defined by a gap betweenrestricting and restricted surfaces that move into contact with eachother when forces on the outboard motor cause a lower portion of theoutboard motor to move by a magnitude greater than a predefined limit ineither the port or starboard directions. Preselected gaps betweenrestricting and restricted surfaces are sized to allow nominal vibrationat low operating speeds of the outboard motor while restrictingexcessive lateral movement during operation at high speed.

U.S. Pat. No. 8,457,820, incorporated by reference herein, discloses amethod is provided by controlling the operation of a marine vesselsubject to porpoising. The method includes sensing an operationalcharacteristic of the marine vessel which is indicative of porpoising ofthe marine vessel, and responding to the sensing of the operationalcharacteristic with a response that is representative of the operationalcharacteristic of the marine vessel as being indicative of theporpoising of the marine vessel.

Unpublished U.S. patent application Ser. No. 14/873,803, filed Oct. 2,2015, and assigned to the Applicant of the present application,incorporated by reference herein, discloses systems and methodsdisclosed herein control position of a trimmable drive unit with respectto a marine vessel. A controller determines a target trim position as afunction of vessel or engine speed. An actual trim position is measuredand compared to the target trim position. The controller sends a controlsignal to a trim actuator to trim the drive unit toward the target trimposition if the actual trim position is not equal to the target trimposition and if at least one of the following is true: a defined dwelltime has elapsed since a previous control signal was sent to the trimactuator to trim the drive unit; a given number of previous controlsignals has not been exceeded in an attempt to achieve the target trimposition; and a difference between the target trim position and theactual trim position is outside of a given deadband.

Unpublished U.S. patent application Ser. No. 15/003,326, filed Jan. 21,2016, and assigned to the Applicant of the present application,incorporated by reference herein, discloses a method for controlling atrim system on a marine vessel includes receiving an actual trimposition of a trimmable marine device at a controller and determining atrim position error by comparing the actual trim position to a targettrim position with the controller. The method also includes determiningan acceleration rate of the marine vessel. In response to determiningthat the trim position error exceeds a first error threshold and themagnitude of the acceleration rate exceeds a given rate threshold, thecontroller commands the marine device to the target trim position. Inresponse to determining that the trim position error exceeds the firsterror threshold and the acceleration rate does not exceed the given ratethreshold, the controller commands the marine device to a setpoint trimposition that is different from the target trim position. An associatedsystem is also disclosed.

Unpublished U.S. patent application Ser. No. 15/003,335, filed Jan. 21,2016, and assigned to the Applicant of the present application, which isincorporated by reference herein, discloses a method for controlling atrim system on a marine vessel includes receiving an actual trimposition of a trimmable marine device at a controller and determining amagnitude of a trim position error by comparing the actual trim positionto a target trim position with the controller. The method also includesdetermining a magnitude of an acceleration rate of the marine vessel.The controller determines the activation time of a trim actuator coupledto and rotating the marine device with respect to the marine vesselbased on the magnitude of the trim position error and the magnitude ofthe acceleration rate. The controller then sends a control signal toactivate the trim actuator to rotate the marine device toward the targettrim position. The method includes discontinuing the control signal oncethe activation time expires to deactivate the trim actuator. Acorresponding system is also disclosed.

SUMMARY

This Summary is provided to introduce a selection of concepts that arefurther described below in the Detailed Description. This Summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter.

In one embodiment, a method of controlling trim position for apropulsion device on a marine vessel includes receiving a running trimposition for the propulsion device, receiving at least one of a steeringinput value or a roll angle of the marine vessel, and determining amagnitude of the steering input value or a magnitude of the roll angleof the marine vessel. The method further includes determining anadjusted trim position based on the magnitude of the steering inputvalue or the magnitude of the roll angle of the marine vessel, andoperating a trim actuator based on the adjusted trim position todecrease the trim angle of the propulsion device below the running trimposition while the marine vessel is turning.

One embodiment of a system for controlling trim position of a propulsiondevice on a marine vessel includes a trim actuator configured to adjustthe trim position of the propulsion device and a controller configuredto control the trim actuator. The controller is further configured toreceive a steering input value or a roll angle of the marine vessel,determine a magnitude of the steering input value or a magnitude of theroll angle of the marine vessel, and determine an adjusted trim positionfor the propulsion device based on the magnitude of the steering inputvalue or the magnitude of the roll angle of the marine vessel. Thecontroller then controls the trim actuator based on the adjusted trimposition to decrease the trim angle of the propulsion device below therunning trim position while the marine vessel is turning.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is described with reference to the followingFigures. The same numbers are used throughout the Figures to referencelike features and like components.

FIG. 1 is a schematic illustration of a marine vessel having a systemfor controlling trim position of a propulsion device.

FIG. 2 depicts one embodiment of a trimmable propulsion device accordingto the present disclosure.

FIG. 3 is a schematic depiction of one embodiment of a trim actuator ina system for controlling trim position of a propulsion device.

FIG. 4 is a schematic diagram depicting another embodiment of a systemfor controlling trim position of a propulsion device.

FIG. 5 exemplifies a relationship between speed and trim position.

FIG. 6A exemplifies a relationship between steering input or roll angleand trim position at a given speed.

FIG. 6B exemplifies a relationship between magnitude of trim positionand speed at a given steering input.

FIG. 7 exemplifies a lookup table that can be used to determine adjustedtrim position.

FIG. 8 exemplifies another lookup table that can be used to determine anadjusted trim position.

FIG. 9 exemplifies a lookup table that can be used to determine amultiplier for determining adjusted trim positions.

FIG. 10 depicts one embodiment of a method for controlling trim positionof a propulsion device.

FIG. 11 depicts another embodiment of a method for controlling trimposition of a propulsion device

DETAILED DESCRIPTION

In the present description, certain terms have been used for brevity,clarity and understanding. No unnecessary limitations are to be inferredtherefrom beyond the requirement of the prior art because such terms areused for descriptive purposes only and are intended to be broadlyconstrued.

The present disclosure relates to systems and methods for controlling atrim actuator on a marine vessel so as to control a relative position ofa propulsion device mounted to the transom of a marine vessel. Thoseskilled in the art of marine vessel propulsion and control are familiarwith many different ways in which the trim angle of a propulsion device,such as an outboard motor or stern drive, can be varied to change thehandling or fuel efficiency of the vessel. For example, many manual trimcontrol systems are known to those skilled in the art. In typicaloperation, the operator of a marine vessel can change the trim angle ofan associated outboard motor as the velocity of the vessel changes. Thisis done to maintain an appropriate angle of the vessel with respect tothe water as it achieves a planing speed and as it increases itsvelocity over the water while on plane. The operator inputs a command tochange the trim angle for example by using a keypad, button, or similarinput device with “trim up” and “trim down” input choices (e.g., seeFIG. 4).

The systems of the present disclosure are also capable of carrying outautomatic trim (auto-trim) methods, in which the propulsion device isautomatically trimmed up or down with respect to its current position,depending on a desired attitude of the marine vessel with respect tovessel speed. Auto-trim systems perform trim operations automatically,as a function of vessel speed, without requiring intervention by theoperator of the marine vessel. The automatic change in trim angle of thetrimmable propulsion device 10 enhances the operation of the marinevessel as it achieves planing speed and as it further increases itsvelocity over the water while on plane. For example, trimming thepropulsion device 10 can affect a direction of thrust of a propellerwith respect to a vessel transom, as well as affect vessel roll andpitch.

FIG. 1 depicts one embodiment of a system 1 for controlling trimposition of a propulsion device 10 on the marine vessel 14. While themethods and systems are described herein with respect to a singlepropulsion device 10, a person of ordinary skill in the art willunderstand in light of this disclosure that the disclosed methods andsystems are equally applicable to marine vessels having more propulsiondevices. Likewise, though the propulsion device 10 is exemplified in theFIGURES as an outboard motor, a person having ordinary skill in the artwill understand in light of this disclosure that the propulsion devicemay also be a stern drive with a trimmable lower unit. The trim positionof the propulsion device 10 is actuated by a trim actuator 16. In oneexample, the trim actuator is a hydraulic piston-cylinder assembly influid communication with a hydraulic pump-motor combination, althoughthe principles of some of the below examples could apply equally toelectric linear actuators, pneumatic actuators, or other types of trimdevices. The trim actuator may be actuated between an extended positionand a retracted position by provision of hydraulic fluid, electricalpower, pneumatic fluid, etc. The extension and retraction of the trimactuator can be used to rotate a trimmable propulsion device up and downwith respect to a marine vessel to which it is coupled.

During cornering at high speeds, the marine vessel 14 rolls toward theport side 11 or starboard side 12 (depending on the direction of theturn). The propulsion device(s) on the turning marine vessel 14 tends tocome out of the water, causing prop venting or blow out. Throughexperimentation and research in the relevant field, the present inventorhas recognized that the problems and issues relating to prop venting ina steep turn can be lessened or prevented by changing the trim of thepropulsion device 10, such as by a feed-forward control method thatadjusts the trim position of the propulsion device as the vessel turns.The inventor has further recognized that utilization of a feed-forwardcontrol system can predict the aggressiveness of a cornering maneuverbased on steering position and/or roll angle and prevent blow out,rather than just reacting to it, by making trim adjustments as thevessel turns and before the propeller breaks through the water surface.For example, the trim position may be decreased (or trimmed in, ortrimmed down) as the marine vessel 14 rolls into a corner and thenincreased (or trimmed out, or trimmed up) as the marine vessel 14 rollsout of a corner so that the drive depth, or the depth of the propeller,remains approximately constant with respect to the surface of the water,regardless of the roll angle of the vessel.

The trimming operation of the trim actuator 16 is controlled bycontroller 38, which is communicatively connected to the trim actuator16 to control activation thereof. The controller 38 controls trim of thepropulsion device 10 by controlling the trim actuator 16, and suchcontrol may be provided as described herein based on one or more ofengine speed, vessel speed, steering input value (such as steering wheelangle), roll angle, and/or running trim position. In the depictedembodiment, the controller 38 receives engine speed, or enginerevolutions per minute (RPM), from the engine control module (ECM) 59 onthe propulsion device 10. The controller 38 also receives a vessel speedfrom vessel speed sensor 56, and receives a roll angle of the marinevessel from the roll sensor 66. The controller 38 also receives asteering input from position sensor 52 on steering input device 54,which in the depicted embodiment is a rotational position sensor 52detecting the rotational position of steering wheel 54. The rotationalposition of the steering wheel may be, for example, measured as an anglewith respect to a centered position 55, which is the position of thesteering wheel 54 associated with a straight ahead steering command. Aperson of ordinary skill in the art will understand in light of thedisclosure that the steering input device 54 may be any number of userinterface devices operable by a user to provide control inputs to steerthe marine vessel, such as a joystick, trackpad, etc., and the positionsensor 52 may be any sensor device that senses movement or input on saiddevices. Alternatively or additionally, the steering input may beprovided by an automatic steering control system associated with themarine vessel 14, such as a heading or waypoint control system.

Referring to FIG. 2, the position of a trimmable propulsion device 10(such as the outboard motor shown herein) with respect to the transom 9of a marine vessel 14 is controlled by a hydraulic trim actuator 16. Thetrim actuator 16 includes a hydraulic piston-cylinder assembly 18connected to a hydraulic pump-motor combination 20. The piston-cylinderassembly 18 has a first end (here, the cylinder end) coupled to thetransom 9 of the vessel 14 and a second, opposite end (here, the rodend) coupled to the propulsion device 10, as known to those havingordinary skill in the art. The piston-cylinder assembly 18 operates torotate the propulsion device 10 about a horizontal trim axis 13 to atrimmed-out position, to a trimmed-in position, or to maintain thepropulsion device 10 in any position there between as the pump-motorcombination 20 provides hydraulic fluid to the piston-cylinder assembly18 to move the piston within the cylinder. As mentioned, however, othertypes of hydro-mechanical or electro-mechanical actuators could be usedin other examples.

One example of a hydraulic trim actuator 16 is shown in FIG. 3. Thepiston-cylinder assembly 18 is shown schematically as having a piston 22connected to a rod 24 disposed in a cylinder 26. The piston 22 defines afirst chamber 28 within the cylinder 26 and a second chamber 30 withinthe cylinder 26, both of which chambers 28, 30 change in size as thepiston 22 moves within the cylinder 26. The pump-motor combination 20includes a pump-motor 32 connected to a trim-in relay 34 and a trim-outrelay 36. In other examples, the trim-in relay 34 and the trim-out relay36 are a single relay that can turn the pump-motor 32 on or off and caneffectuate a trim-in or trim-out movement of the trim actuator 16. Therelays 34 and 36 are connected to a controller 38 that controlsenergizing of solenoids in the relays 34 and 36, which act as switchesto couple a power source such as a battery (not shown) to chamber 28 ofthe piston-cylinder assembly 18, and a second hydraulic line 42 couplesthe pump-motor 32 to the second chamber 30 of the piston-cylinderassembly 18. As long as the trim-in relay 34 is activated, thepump-motor 32 provides hydraulic fluid through the first hydraulic line40 to the first chamber 28 of the piston-cylinder assembly 18, therebypushing the piston 22 downwardly within the cylinder 26 and lowering(trimming in, or trimming down) the propulsion device 10 coupled to therod 24. As long as the trim-out relay 36 is activated, the pump-motor 32provides hydraulic fluid through the second hydraulic line 42 to thesecond chamber 30 of the piston-cylinder assembly 18, thereby pushingthe piston 22 upwardly within the cylinder 26 and raising (trimming out,or trimming up) the propulsion device 10 coupled to the rod 24.Hydraulic fluid can be removed from the opposite chamber 28 or 30 of thecylinder 26 into which fluid is not being pumped in either instance, anddrained to a tank or circulated through the pump-motor 32.

In this way, the trim actuator 16 can position the propulsion device 10at different angles with respect to the transom 9. These may be aneutral (level) trim position, in which the propulsion device 10 is inmore or less of a vertical position; a trimmed in (trimmed down)position; or a trimmed out (trimmed up) position. A trimmed outposition, as shown in FIG. 2, is often used when the marine vessel 14 ison plane and high speeds are required. At high speeds, the trimmed outposition causes the bow of the marine vessel 14 to rise out of thewater, resulting in better handling and increased fuel efficiency. Thus,many auto-trim algorithms include determining a target running trimposition at which to orient the propulsion device 10 with the controller38 based on speed, such as but not limited to engine speed, vesselspeed, a combination of vessel speed and engine speed, or a tradeoffbetween vessel speed and engine speed depending on additional vesselconditions. Examples of such systems are shown and described in U.S.Pat. No. 7,416,456; and application Ser. Nos. 14/873,803; 15/003,326;15/003,335, which are incorporated herein by reference.

The controller 38 may define the running trim position by reference to avertical line V. When the centerline CL of the propulsion device 10 isparallel to the vertical line V, the controller 38 may consider this tobe zero trim. Trim position can be quantified as a value P with respectto the vertical line V, which represents the angle or comparativeposition between the centerline CL of the propulsion device 10 and thevertical line V. This value P can be expressed as an angle, a percentageof a total angle to which the propulsion device 10 can be trimmed, ascalar value, a polar coordinate, or any other appropriate unit. Forpurposes of the description provided herein below, the angle P will beexpressed as a percentage of total allowable trim angle, which can bemeasured from vertical, from a fully trimmed out position, or from afully trimmed in position.

FIG. 4 shows a schematic of an embodiment of the system 1 forcontrolling trim position. In the example shown, the system 1 includescontroller 38, which is programmable and includes a processor 46 and amemory 48. The controller 38 can be located anywhere on the marinevessel 14 and/or located remote from the marine vessel 14 and cancommunicate with various components of the system 1 via wired and/orwireless communication links, as will be explained further herein below.Although FIGS. 1 and 3 show a single controller 38, the system 1 mayinclude more than one controller 38. For example, the system 1 may havea controller 38 located at or near a helm of the marine vessel 14 andcan also have one or more controllers located at or near the propulsiondevice 10. The controller 38 may be a dedicated device, or may beincorporated in and a function of a multi-function control device, suchas incorporated into a helm control module (HCM) or other control deviceand software communicatively connected to the ECM 59. Portions of themethod disclosed herein below can be carried out by a single controlleror by several separate controllers.

In some examples, the controller 38 may be a computing system thatincludes a processing system, storage system, software, and input/output(I/O) interfaces for communicating with devices such as those shown inFIG. 4, and described herein. The processing system loads and executessoftware from the storage system, such as software programmed with atrim control method. When executed by the computing system, trim controlsoftware directs the processing system to operate as described herein toexecute the trim control method. The computing system may include one ormany application modules and one or more processors, which may becommunicatively connected. The processing system can comprise amicroprocessor (e.g., processor 46) and other circuitry that retrievesand executes software from the storage system. Processing system can beimplemented within a single processing device but can also bedistributed across multiple processing devices or sub-systems thatcooperate in executing program instructions. Non-limiting examples ofthe processing system include general purpose central processing units,application specific processors, and logic devices.

The storage system (e.g., memory 48) can comprise any storage mediareadable by the processing system and capable of storing software. Thestorage system can include volatile and non-volatile, removable andnon-removable media implemented in any method or technology for storageof information, such as computer readable instructions, data structures,program modules, or other data. The storage system can be implemented asa single storage device or across multiple storage devices orsub-systems. The storage system can further include additional elements,such as a control circuitry capable of communicating with the processingsystem. Non-limiting examples of storage media include random accessmemory, read only memory, magnetic discs, optical discs, flash memory,virtual memory, and non-virtual memory, magnetic sets, magnetic tape,magnetic disc storage or other magnetic storage devices, or any othermedium which can be used to store the desired information and that maybe accessed by a processing system. The storage media can be anon-transitory or a transitory storage media.

In this example, the controller 38 communicates with one or morecomponents of the system 1 via a communication link 50, which can be awired or wireless link. The controller 38 is capable of monitoring andcontrolling one or more operational characteristics of the system 1 andits various subsystems by sending and receiving control signals via thecommunication link 50. In one example, the communication link 50 is acontroller area network (CAN) bus, but other types of links could beused. It should be noted that the extent of connections of thecommunication link 50 shown herein is for schematic purposes only, andthe communication link 50 in fact provides communication between thecontroller 38 and the sensors, devices, etc. described herein, althoughnot every connection is shown in the drawing for purposes of clarity.

As mentioned, the controller 38 receives inputs from several differentsensors and/or input devices aboard or coupled to the marine vessel 14.For example, the controller 38 receives a steering input from a steeringposition sensor 52 that senses a position or angle of a steering inputdevice, such as a joystick and/or a steering wheel 54. As describedabove, the steering input may also be provided by an automatic steeringcontrol system. The controller 38 may also be provided with an inputfrom a vessel speed sensor 56. The vessel speed sensor 56 may be, forexample, pressure-type sensor, such as pitot tube 56 a, a paddle wheeltype sensor 56 b, or any other speed sensor appropriate for sensing theactual speed of the marine vessel. Alternatively or additionally, thevessel speed may instead be determined based on readings from a GPSdevice 56 c, which calculates speed by determining how far the vessel 14has traveled in a given amount of time. The propulsion device 10 mayalso be provided with an engine speed sensor 58, such as but not limitedto a tachometer, that determines a speed of the engine 60 powering thepropulsion device 10 in rotations per minute (RPM). The engine speed canbe used along with other measured or known values to approximate avessel speed (i.e., to calculate a pseudo vessel speed). A trim positionsensor 62 may also be provided for sensing an actual position of thetrim actuator 16, for example, by measuring a relative position betweentwo parts associated with the trim actuator 16. The trim position sensor62 may be any type of sensor known to those having ordinary skill in theart, for example a Hall effect sensor or a potentiometer, such asexamples provided and described in U.S. Pat. No. 6,322,404 incorporatedherein by reference. The controller 38 may also receive inputs from aroll sensor 66 that senses a roll position, such as an angle withrespect to horizontal. For example, the roll sensor 66 may comprise agyroscope, such as a three-axis gyroscope, to detect orientationinformation that may be used to determine the roll angle of the marinevessel 14. In other embodiments, the roll sensor 66 may be amagnetometer, or may include any other type of position or inertialmeasurement unit, such as a combination accelerometer and/or gyroscopewith a magnetometer.

Other inputs to the system 1 can come from operator input devices suchas a throttle lever 68, a keypad 70, and a touchscreen 64. The throttlelever 68 allows the operator of the marine vessel to choose to operatethe vessel in neutral, forward, or reverse, as is known. The keypad 70can be used to initiate or exit any number of control or operation modes(such as auto-trim mode), or to make selections while operating withinone of the selected modes. In one example, the keypad 70 comprises aninterface having a “trim up” button 70 a, a “trim down” button 70 b, andan “auto-trim on/resume” button 70 c, which can be utilized by a user tocontrol the running trim position of the propulsion device 10. Forexample, the trim buttons 70 a and 70 b may provide user input tocontrol the propulsion device to the same running trim position. Thetouchscreen 64 can also be used to initiate or exit any number ofcontrol or operation modes (such as trim up, trim down, or auto-trimmode), and in that case the inputs can be buttons in the traditionalsense or selectable screen icons. The touchscreen 64 can also displayinformation about the system 1 to the operator of the vessel 14, such asengine speed, vessel speed, trim angle, trim operating mode, vesselacceleration rate, etc. Additionally, the touchscreen 64 may replace thekeypad 70, providing the trim buttons 70 a-70 b.

As described above, the present inventor has recognized trim of thepropulsion device 10 on a marine vessel can be automatically controlledto discreetly control the propulsion device 10 to different trim anglesduring cornering at high speeds in order to avoid prop venting by thepropulsion device 10. Namely, the propulsion device 10 can be trimmed in(or trimmed down, or trim decreased) from the running trim position inorder to keep the propeller underneath the surface of the water.

FIG. 5 depicts a graphical representation showing the relationshipbetween running trim position and speed, which may be engine RPM orvessel speed, which is applied when the marine vessel 14 is traveling inthe straight ahead direction. The graph of FIG. 5 provides an example ofhow trim may be automatically controlled by an auto-trim system withrespect to speed; however, a person having ordinary skill in the artwill also understand in light of this disclosure that the methoddisclosed herein of controlling trim during cornering maneuver may alsobe applied in situations where the propulsion device 10 is controlledmanually to a running trim position (such as via trim buttons 70 a and70 b). As used herein, the running trim position refers generally to thecurrent instructed or target trim position for the propulsion device 10on a marine vessel based on the current running condition of thepropulsion device and/or based on user input. Thus, the running trimposition may be automatically controlled and instructed by an auto-trimsystem based on speed (vessel speed and/or engine RPM) or may bemanually controlled by a user. The running trim position may further bea stored value, such as from the auto-trim system and/or a user controlsetting, or it may be a measured value, such as from the trim positionsensor 62 associated with the trim actuator 16.

As described above, the running trim position of the propulsion deviceis generally increased as the vessel speed increases and the propulsiondevice 10 is generally trimmed out (applying positive trim) at highspeeds when the marine vessel is on plane. As depicted in FIG. 5, therunning trim position 72 generally increases as speed increases. In thedepicted example, the running trim position 72 is the value on the trimposition curve 71 at the current speed 77. In the depicted relationshipthe running trim increases generally proportionally with the speedbetween the lower speed threshold 76 and the upper speed threshold 78.The propulsion device 10 is movable to a maximum positive trim position74 (or maximum trim out position). In the graph, zero trim representsthe vertical position when the propulsion device 10 is in line withvertical line V (FIG. 2). Negative trim positions, or trim in positions,are represented below the zero point on the trim position axis. In thedepicted embodiment, the propulsion device 10 is maintained in a trimmedin position until the vessel reaches a lower speed threshold, which maybe at or near the planing speed. Below the lower speed threshold 76, thetrim position is maintained at a constant value. Likewise, above anupper speed threshold 78 the trim is also maintained at a constantvalue. This avoids making trim adjustments at speed below the planingspeed and at very high speeds. Avoiding adjustment at very high speedsmay be desirable in certain embodiments because adjusting trim at veryhigh speeds may introduce unwanted instability for certain marinevessels 14. Accordingly, running trim position is only adjusted withinan operating range OR between a lower speed threshold 76 and an upperspeed threshold 78. In that range, the running trim position isdetermined based on the current speed 77 and the relationship isdepicted by the trim position curve 71. The relationship between speedand running trim position may be linear or curvilinear, and may vary,for example, based on vessel configuration.

FIG. 6A provides a graph exemplifying a possible relationship betweenmagnitude of the steering input value (exemplified as steering angle)and trim position at a given speed, such as a planing speed (speed wherethe vessel is on plane) or a speed above the lower speed threshold 76.In a given system 1, the relationship between steering input and trimposition may vary at different speeds, and thus the graph may lookdifferent at different speeds. The y-axis represents trim, with therunning trim position 72 providing a center point, or axis, around whichthe trim position of propulsion device 10 is adjusted with respect tothe steering angle magnitude, represented on the x-axis.

Generally, the trim position of the propulsion device 10 is reduced(trimmed in) while the marine vessel 14 is turning, and the trimreduction is applied equally in either turn direction (i.e., toward theport side 11 or starboard side 12). In the depicted embodiment, the trimposition remains at the running trim position 72 value until themagnitude of the steering input, which in this case is steering angle ofsteering wheel 54, reaches a threshold steering angle 81. Once thesteering wheel 54 is moved past that threshold steering angle 81 thetrim position of the propulsion device 10 is adjusted as depicted. Forinstance, the magnitude of the trim adjustment amount (i.e., subtractedfrom the running trim angle 72) increases as the steering wheel 54 isturned away from the centered position 55 (i.e. as the magnitude of thesteering angle increases) towards a maximum steering angle 85, which inthis example is the steering end stop. Likewise, as the steering wheel54 is turned back towards the centered position 55, the trim position isreturned to the running trim angle 72. This relationship also holds truein an embodiment controlled based on roll angle, where the trim islikewise reduced by an increasing amount as the roll angle of the marinevessel 14 increases.

The adjusted trim position 88 may be adjusted during a turn to accountfor changes in speed, vessel speed or engine speed. If vessel speed doesdecrease during the course of a turn (e.g. because of a user reducingthe throttle demand) the running trim position 72 will decrease, such asalong the exemplary curve of FIG. 5, and the adjusted trim position 88can be changed accordingly to account for the new running trim position72. Vessel speed can be accounted for directly in the determination ofadjusted trim position, or indirectly by basing it on running trimposition 72.

FIG. 6B provides another graph describing an exemplary relationshipbetween the magnitude of trim adjustment (e.g., the difference betweenthe running trim angle and the adjusted trim position) and speed for aparticular steering input value or roll angle. The depicted trimadjustment is applied to reduce the running trim position. In theexample, the magnitude of the trim adjustment is zero below the lowerspeed threshold 76, increases to a maximum, then decreases as itapproaches the upper speed threshold 78, and is zero above the upperspeed threshold 78. Accordingly, trim adjustments are only made in theoperating range (OR) between the lower speed threshold 76 and the upperspeed threshold 78. While the depicted example avoids trim adjustmentsabove the upper speed threshold 78, in other embodiments where suchinstability at the vessel's maximum speeds is not an issue, the curvemay be shaped to provide the maximum trim adjustment magnitude at thehigh speed values. The depicted parabolic relationship between speed andtrim adjustment magnitude is merely exemplary, and in other embodimentsthe relationship may be linear or curvilinear, and may vary, forexample, based on vessel configuration. Likewise, the curve may lookdifferent for different running trim positions.

In one embodiment, the trim adjustment amount between the running trimposition 72 and the adjusted trim position is calibrated based on thevessel configuration, such as to account for the hull configuration ofthe marine vessel 14 and the positioning of the propulsion devise 10thereon. For instance, the adjusted trim position 88 may be determinedfor the propulsion device 10 by accessing a lookup table based on one ormore of the steering input value, the roll angle, the vessel speed, theengine RPM, and the running trim position, where the values in thelookup table are calibrated for the particular marine vessel 14configuration.

FIG. 7 depicts one exemplary lookup table 91 providing adjusted trimpositions 88 for the propulsion device 10 based on magnitude of thesteering input value or roll angle and the speed, which could be thevessel speed or the engine speed. The values associated with the zerosteering angle will be equal to the running trim position 72 at thatspeed. Adjusted trim positions 88 (e.g. one for each propulsion device10 on the marine vessel 14) are provided in the lookup table 91 forsteering input values or roll angle increments. The trim actuator 16 isthen operated to move the associated propulsion device 10 towards itsrespective adjusted trim position 88.

FIG. 8 depicts one exemplary embodiment, where a lookup table 91contains trim adjustment values 93 based on running trim position andsteering input or roll angle. The trim adjustment values 93 may be anyvalues upon which the adjusted trim positions 88 for the propulsiondevice 10 can be determined. For example, the trim adjustment values 93may include trim adjustment amounts for the propulsion device 10, whichcould then be subtracted from the running trim position 72.Alternatively, the trim adjustment values 93 may be the actual adjustedtrim positions 88, where no further calculation is necessary. In thedepicted example, the lookup table 91 contains trim adjustment values 93for steering input magnitude. In other embodiments, the lookup table 91may be based on steering input magnitude or roll angle magnitude, andadditional logic may be applied to determine whether the trim adjustmentvalues 93 should be applied to trim in the propulsion device.

In embodiments where the auto trim feature is in effect, and thus therunning trim position 72 is determined based on speed (e.g., engine RPMor vessel speed), the running trim position value on the lookup table 91will account for speed for purposes of determining the adjusted trimposition. In embodiments where the running trim position 72 is set by auser, and thus may not correlate to speed with the desired accuracy, itmay be desirable to apply a multiplier to the trim adjustment values 93to ensure that trim adjustments are not applied outside of the operatingrange, or at least above the upper speed threshold 78. FIG. 9 depicts anexemplary one-dimensional lookup table 95 containing multiplier values Xbased on speed (e.g., engine RPM or vessel speed). Such a multiplier mayaccount for the operating range OR of speeds discussed with respect toFIG. 5, and thus may operate to ensure that the trim position is notadjusted at speeds below a lower speed threshold 76 or above an upperspeed threshold 78, and may also taper the speed adjustment (e.g., asexemplified in FIG. 6B). Similarly, such a multiplier table could beused in conjunction with one dimensional table providing a trimadjustment values based on steering input value or roll angle.

FIG. 10 is a flowchart depicting one embodiment of a method 100 ofcontrolling trim position. The running trim position is received at step102. As discussed above, the running trim position indicates the currenttrim position setting, which may be automatically controlled and setbased on current conditions, such as speed, or may be a user set trimposition. The running trim position may be the current value of avariable stored by an auto-trim control process, such as a value storedin memory 48 and retrievable by the processor 46. Alternatively, therunning trim position may be received from the trim position sensor 62,reflecting the actual measured current trim position of the propulsiondevice 10. At step 104, the steering input and/or roll angle arereceived, such as from the steering position sensor 52 or the rollsensor 66. An adjusted trim position is determined for the propulsiondevice 10 is then determined based at least on the steering input valueor the roll angle of the marine vessel at step 110. For example, theadjusted trim position may be determined via one or more of the lookuptables exemplified in FIGS. 7-9 and correspondingly described. The trimposition of the propulsion device 10 is then reduced toward itsrespective adjusted trim position at step 112, such as by sendingcontrol signals to the trim actuators 16 to operate accordingly.

The method 100 of controlling trim position may be executed, forexample, by the controller 38 executing software stored in memory 48 onprocessor 46. Alternatively or additionally, portions of the method maybe executed by other control devices or modules, such as by a helmcontrol module (HCM) for the marine vessel 14 and/or by the respectiveECMs 59 for the propulsion device 10.

FIG. 11 depicts another exemplary embodiment of a method 100 forcontrolling trim position. The running trim position is received at step102, and steering input and/or roll angle are received at step 104 asdescribed above. At step 105, the current speed is received. At step107, the steering input and/or roll angle received at step 104 arecompared to a threshold for that value type, where the threshold isidentified based on the vessel speed received at step 105. Thus, thethreshold for determining whether trim adjustment should be made isvariable based on vessel speed. For example, the threshold for makingtrim adjustments may decrease as vessel speed increases, therebyincreasing the trim reactiveness to turning maneuvers as vessel speedincreases. In reference to embodiments disclosed and described herein,the vessel speed may be received, for example, from any one or more ofthe exemplary vessel speed sensors 56 described herein, including thepitot tube sensor 56 a, paddle wheel sensor 56 b, or GPS system 56 c.Alternatively or additionally, steps 105 and 107 may be based on enginespeed, such as from an engine speed sensor 58 on the propulsion device10. For example, the engine speed may be tracked by and received fromeach respective ECM 59. If the steering input and/or roll angle do notexceed the threshold then the method returns to step 102, continuallymonitoring the steering input and/or roll angle and comparing it tothresholds based on speed. In certain embodiments, the steering inputand/or roll angle inputs may be filtered to prevent excessive trimcycling based on minor and momentary steering or roll changes.

Once the threshold is exceeded at step 107, the trim adjustment value isdetermined based on the steering input and/or roll angle at step 108.For example, the trim adjustment value may be determined utilizing alookup table comparing trim position and steering input or roll angle,such as a one dimensional lookup table or a two dimensional lookup tablebased on running trim angle such as that exemplified and described abovein FIG. 8. For example, the lookup table may be a one dimensional lookuptable providing trim angle adjustment amounts based one speed. Inembodiments where the trim angle adjustment is pegged to running trimposition but the running trim position is set by a user (rather thanautomatically determined based on speed) and thus may not be tieddirectly or exactly to the vessel speed or engine speed, the system 1may execute step 109 to determine a multiplier based on the vessel speed(or engine speed), thus ensuring that the trim adjustment is notinappropriate for the current vessel speed. As described elsewhereherein, significant trim adjustments at high speeds may have potentialfor creating instability for the marine vessel 14, and thus significanttrim adjustments may be avoided by including a multiplier that is lessthan one, or even equal to zero to reduce or eliminate trim adjustmentat high speeds. As exemplified above with respect to FIG. 9, themultiplier may be determined by accessing a one-dimensional lookup table95 correlating multiplier X values to speed increments, where trimadjustments at high speed values may have multiplier values X thatapproach or are equal to zero. For example, the multiplier X may be zerobelow the lower speed threshold 76 and/or above the upper speedthreshold 78. Likewise, the multiplier X value may be significantly lessthan 1 and decrease as it approaches the lower speed threshold 76 and/orthe upper speed threshold 78. The adjusted trim position for thepropulsion device 10 is determined at step 110, such as by multiplyingthe trim adjustment value determined at step 108 by the multiplierdetermined at step 109. The adjusted trim position is then compared tothe running trim position at step 111 to make sure that the adjustedtrim position is less than (or a more trimmed in position) than therunning trim position. If so, the actuator 16 is then controlled to movethe propulsion device 10 towards its adjusted trim position at step 112.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to make and use the invention. Certain terms have been used forbrevity, clarity and understanding. No unnecessary limitations are to beinferred therefrom beyond the requirement of the prior art because suchterms are used for descriptive purposes only and are intended to bebroadly construed. The patentable scope of the invention is defined bythe claims, and may include other examples that occur to those skilledin the art. Such other examples are intended to be within the scope ofthe claims if they have features or structural elements that do notdiffer from the literal language of the claims, or if they includeequivalent features or structural elements with insubstantialdifferences from the literal languages of the claims.

What is claimed is:
 1. A method of controlling trim position of apropulsion device on a marine vessel, the method comprising: receiving arunning trim position for the propulsion device; receiving at least oneof a steering input value or a roll angle of the marine vessel;determining a magnitude of the steering input value or a magnitude ofthe roll angle of the marine vessel; determining an adjusted trimposition based on the magnitude of the steering input value or themagnitude of the roll angle of the marine vessel; and operating a trimactuator based on the adjusted trim position to decrease the trim angleof the propulsion device below the running trim position while themarine vessel is turning.
 2. The method of claim 1, further comprisingincrementally decreasing the trim angle as the magnitude of the steeringinput value or the magnitude of the roll angle increases.
 3. The methodof claim 2, further comprising incrementally increasing trim angle asthe magnitude of the steering input value or the magnitude of the rollangle decreases such that the propulsion device is at the running trimposition upon completion of the turning.
 4. The method of claim 1,wherein the steering input value is an angular position of a steeringwheel with respect to a centered position.
 5. The method of claim 1,further comprising determining that the magnitude of the steering inputvalue is greater than a threshold steering input or the magnitude of theroll angle is greater than a threshold roll angle, and then determiningthe adjusted trim position.
 6. The method of claim 1, wherein therunning trim position is determined by a controller based on a vesselspeed and/or an engine speed.
 7. The method of claim 6, whereindetermining the adjusted trim position includes accessing a lookup tableof adjusted trim positions based on either the steering input value orthe roll angle and the running trim position.
 8. The method of claim 1,wherein the running trim position is determined based on input from atrim position sensor.
 9. The method of claim 1, wherein determining theadjusted trim position includes accessing a lookup table based on eitherthe steering input value or the roll angle and on either a vessel speedor an engine speed.
 10. The method of claim 9, wherein the lookup tableis configured to minimize the difference between the running trimposition and the adjusted trim position when the vessel speed or theengine speed is less than a lower speed threshold or greater than anupper speed threshold.
 11. A system for controlling trim position of apropulsion device on a marine vessel, the system comprising: a trimactuator configured to adjust a trim position of the propulsion device;a controller configured to: receive a steering input value or a rollangle of the marine vessel; determine a magnitude of the steering inputvalue or a magnitude of the roll angle of the marine vessel; determinean adjusted trim position for the propulsion device based on themagnitude of the steering input value or the magnitude of the roll angleof the marine vessel; and control the trim actuator based on theadjusted trim position to decrease the trim angle of the propulsiondevice below the running trim position while the marine vessel isturning.
 12. The system of claim 11, wherein the controller receives thesteering input value, wherein the steering input value is an angularposition of a steering wheel with respect to a centered positionmeasured by a steering position sensor.
 13. The system of claim 11,wherein the controller receives the roll angle, wherein the roll angleis an angular position of the marine vessel with respect to horizontalmeasured by a roll angle sensor.
 14. The system of claim 11, wherein thetrim angle is incrementally decreased as the magnitude of the steeringinput value or the magnitude of the roll angle increases.
 15. The systemof claim 14, wherein the trim angle is incrementally increased as themagnitude of the steering input value or the magnitude of the roll angledecreases such that the propulsion device is at the running trimposition upon completion of the turning.
 16. The system of claim 11,wherein the controller further determines that the magnitude of thesteering input value is greater than a threshold steering input or amagnitude of the roll angle is greater than a threshold roll anglebefore determining the adjusted trim position.
 17. The system of claim11, further comprising a lookup table accessible by the controller fordetermining the adjusted trim position, the lookup table listing trimadjustment values based on either the steering input value or the rollangle and the running trim position.
 18. The system of claim 11, whereinthe controller is further configured to receive an engine speed and/or avessel speed and determine the running trim position based on the vesselspeed and/or the engine speed.
 19. The system of claim 18, furthercomprising a lookup table accessible by the controller for determiningthe adjusted trim position, the lookup table listing trim adjustmentvalues based on either the steering input value or the roll angle and oneither the vessel speed or the engine speed.
 20. The system of claim 19,wherein the lookup table is configured to minimize the differencebetween the running trim position and the adjusted trim position whenthe vessel speed or the engine speed is less than a lower speedthreshold or greater than an upper speed threshold.